study of skb264 for locally advanced, recurrent or metastatic hr+/her2- breast cancer

Conditions: Metastatic Breast Cancer

Summary: the purpose of this study is to evaluate the efficacy and safety of skb264 in patients with unresectable locally advanced, recurrent, or metastatic hr+/her2- breast cancer.

this is a randomized, open-label, multicenter phase 3 clinical study to evaluate skb264 monotherapy versus treatment of physician's choice (tpc) in subjects with unresectable locally advanced, recurrent, or metastatic hr+/her2- breast cancer who had failed at least one line of systemic chemotherapy.

Eligibility criteria:
inclusion criteria: * males or females aged ≥ 18 to ≤ 75 years at the time of signing the icf; * histologically and/or cytologically confirmed hr+/her2- breast cancer based on pathology reports on recent biopsy specimens or other pathological samples; * patients who had failed at least one line of systemic chemotherapy in unresectable locally advanced, recurrent, or metastatic stage; * patients with at least one measurable lesion per recist 1.1 criteria; those with only skin or bone lesions cannot be included; * eastern cooperative oncology group (ecog) performance status score of 0 to 1; * expected survival ≥ 12 weeks; * adequate organ and bone marrow function; * patients who are eligible for a chemotherapy regimen in the control group; * female patients of childbearing potential and male patients with partners of childbearing potential who use effective medical contraception from the time of signing the informed consent form until 6 months after the last dose; * patients who voluntarily participate in the study and sign the icf, and able to comply with the visit and related procedures stipulated in the plan. exclusion criteria: * patients with a history of central nervous system (cns) metastases or current cns metastases； * patients with other malignancies (except cured basal or squamous cell skin cancer or carcinoma in situ of the cervix) within 3 years prior to the first dose; * patients with any cardio cerebral vascular disease or cardio cerebral vascular risk factors may affect investigational treatment; * uncontrollable systemic diseases assessed by the investigator; * history of (noninfectious) interstitial lung disease (ild)/noninfectious neumonitis requiring steroid therapy and current ild/noninfectious pneumonitis, or ild/noninfectious pneumonitis at screening that cannot be excluded by imaging; * clinically serious lung injuries caused by lung diseases; * patients with active chronic inflammatory bowel disease, gastrointestinal obstruction, severe ulcer, gastrointestinal perforation, abdominal abscess or acute gastrointestinal bleeding; * toxicities from prior anti-tumor therapy not recovering to ≤ grade 1; * active hepatitis b or hepatitis c; * human immunodeficiency virus (hiv) antibody test positive or a history of acquired immunodeficiency syndrome (aids), known active syphilis infection; * known allergy or hypersensitivity to skb264, or the excipients of skb264; * prior trop2 targeted therapy, prior topoisomerase i inhibitor therapy, including antibody-drugconjugate(adc) therapy; * patients who received major surgeries 4 weeks prior to the first dose of study treatment or planned to receive major surgeries during the study ; * patients with concomitant infections requiring systemic antibiotic therapy within 2 week prior to the first dose of study treatment; * patients who have received live vaccines within 30 days prior to the first dose, or are scheduled to receive live vaccines during the study; * pregnant or lactating women.